It would be nice to have this option available in the next update. Could you please let me know how I can do this with cron job until the next update?

I'm not sure if this will be implemented as a feature. It sounds more like a job for a management/billing software like whmcs. You can create a own php or shell script and use vestacp api https://vestacp.com/docs/api/ and the command v-suspend-user.